JPH0237057A - Car maintenance interval-monitor and method of monitoring car maintenance interval - Google Patents

Abstract

PURPOSE: To precisely perform a plurality of different maintenance works by comparing a traveling approximate distance with each maintenance intervals and, and when the traveling approximate distance exceeds one of maintenance intervals, displaying the corresponding maintenance item. CONSTITUTION: A microcomputer 50 calculates the vehicle traveling time from the ON signal of an ignition switch and also calculate the traveling approximate distance by multiplying a vehicle speed rate value. A computer C stores a plurality of maintenance intervals to the vehicle in a RAM 58, compares the traveling approximate distance with each maintenance interval followed by arithmetic operation, and displays the remaining traveling distance to each maintenance interval as occasion demands on a display part 62 and, further, when the traveling approximate distance exceeds one maintenance interval, it displays this maintenance item and gives an alarm 67. Thus, a plurality of maintenance works can be properly performed according to preset maintenance intervals.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to maintenance interval monitors, particularly those designed for use with motor vehicles.

[Conventional technology]

Maintenance of modern motor vehicles is extremely important due to the constant increase in the cost of new vehicles and the increase in the cost of major maintenance on vehicles. Major maintenance on motor vehicles can be omitted or delayed if appropriate attention is paid to a relatively small number of items. Proper maintenance of these items will extend the time between major maintenance and extend the life of the vehicle.

Therefore, it is important that vehicle owners be aware of the need to perform maintenance on these items.

Generally important items require maintenance to be performed at different and discrete intervals. For this reason, it is difficult for owners to keep track of which items require maintenance and at what intervals.

Moreover, maintenance intervals vary depending on the actual usage conditions of the vehicle. For example, if a vehicle is only used for short trips, the oil must be changed frequently;
If the vehicle is used only for long highway trips, more mileage will be gained between oil changes than if the vehicle is used for short trips. This variability in usage further complicates the problem of vehicle maintenance since manufacturer maintenance recommendations generally cover only total mileage figures, thus creating many suboptimal maintenance conditions. For these reasons, many types of maintenance interval monitors have been proposed.

For example, US Pat. No. 4,031,363 included an electronic monitor that indicates the need for vehicle maintenance after certain time intervals or after certain distance intervals.

Distance traveled was determined by a speed cable or other total mileage sensor. This monitor did not allow the vehicle owner to change the interval.

U.S. Pat. No. 4,159,531 was directed to an electronic maintenance instruction system. When the system was timed, it indicated the next mileage to be serviced and the name of the maintenance job to be performed. The suggested mileage between maintenance tasks could not be changed by the user, and there were no instructions indicating when maintenance should be performed.

This system also allowed for the storage of actual mileage when maintenance was performed by appropriate equipment, but required special equipment to store the values.

No. 4,307,291, a mechanical maintenance monitor having a series of rotatable wheels was driven by the vehicle's speedometer cable.

An electrical circuit was closed to indicate completion of the set interval. Although a number of different intervals corresponding to different maintenance tasks could be set according to the manufacturer's standard, maintenance intervals could not be adjusted by the owner.

U.S. Pat. No. 4,404,641 discloses an electronic equipment maintenance monitor that compares elapsed travel time to an owner selectable time value to enable alarm indicators and equipment deactivation devices.

[Problem to be solved by the invention]

These devices have generally been inadequate for maintenance monitoring of motor vehicles. The monitor must be extremely easy to install in the vehicle. If this were facilitated, devices requiring cumbersome electrical connections or connections to the vehicle's speedometer cable would be unnecessary. Some people object to connecting other instruments other than the speedometer to the speedometer cable. Since mileage is a common criterion used for purposes of determining maintenance needs, the monitor must use mileage accumulated for determining maintenance intervals.

This eliminates the need for a device that measures only the elapsed time. The monitor must allow the user to individually select or change maintenance intervals to allow for differences in the use of individual vehicles. This eliminates the need for a device in which maintenance intervals can only be set by the manufacturer.

[Means to solve the problem]

In summary, the present invention provides a new and improved programmable motor vehicle maintenance interval monitor. This monitor is computer based and the only connections the vehicle requires are to the battery and ignition circuit.

As the vehicle is running, the monitor also displays six maintenance items and the number of miles remaining before each item requires maintenance. When the vehicle is not running, the display on the monitor shows the date and time. When the number of miles remaining for a maintenance item passes 0, the beep
An alarm system such as er) will sound to indicate the need to perform maintenance on that service item. After the item is serviced, the owner also enters the desired number of miles before servicing the item. Additionally, the owner may change the remaining miles in any manner at any time to allow for a change in vehicle usage or early maintenance.

The number of miles elapsed based on vehicle travel is calculated from vehicle travel time. The monitor determines a calculated time based on the vehicle's travel since the last mileage calculation was performed and multiplies this time by a speed factor to approximate the distance traveled since the last mileage calculation. Mileage calculations are done frequently to minimize starting and ending errors. The speed factor can be changed by the owner to better match individual driving conditions.

〔Example〕

In the drawing, a monitor module M (Fig. 1) including an interface unit I-I and a computer 〇 is shown.
is shown electrically connected to the battery 20 of the vehicle (2). The monitor module M of the present invention allows a vehicle operator or maintenance personnel to determine when to perform any of a selected number of maintenance items or tasks. As will be explained hereinafter, the monitor module M of the present invention is capable of separately monitoring a number of maintenance items at the same or different intervals, six in the preferred embodiment. Furthermore, individual intervals can be selectively varied as the vehicle usage needs or circumstances change. As usual, the vehicle's battery 20 is electrically connected to the ignition switch 22. The remainder of the vehicle's electrical system is conventional and is not shown for this reason. A protective full wave rectifier diode bridge 24 is connected to the battery 20 for the purpose of preventing damage to the monitor module M should the vehicle battery 20 leads or monitor connections be reversed.

The output lead wire of the full-wave rectifier diode bridge 24 is connected in series with a current limiting resistor 26 and a first battery 28.
and connected to the second battery row 30. A second battery bank 30 provides operating DC power at the required voltage level to the computer (FIG. 2) employed within the monitor module M. The first battery 28 raises the overall voltage present at one input to the current limiting resistor 26 to a higher level, preferably to the level of the vehicle's battery 20, reducing the power dissipated in the current limiting resistor 26. , thus extending vehicle battery life and reducing current leakage.

The first battery 28 and the second battery bank 30 are energized to protect the computer from undervoltage conditions during vehicle starting, overvoltage conditions due to defects in the vehicle's electrical system, and other transient conditions present in the vehicle's electrical system. Performs additional functions of regulation and transient cancellation.

A bias resistor 32 and relay 34 of the interface unit are electrically connected to the vehicle's ignition switch 22. Biasing resistor 32 is used to provide the appropriate operating voltage or current to coil 35 of relay 34. Relay 34 also includes a unipolar normally closed contact 36 connected to computer 0 through conductors 38 and 40. The unipolar normally closed contact 36 is normally open, so when the vehicle ignition is off the unipolar normally closed contact 36 is closed, whereas when the vehicle ignition is on the unipolar normally closed contact 36 is open. It will be done. In this way, the monitor module M determines when the vehicle is operating.

There are 3 cables between Monitor Monjoor M and the vehicle's electrical system
It should be noted that there are only one type of connection: to earth, to the positive terminal of the vehicle's battery 20 and finally to the ignition switch 22.

These are very simple connections, generally available at the fuse panel of a vehicle, which allow for easy installation on many types of vehicles by persons of varying skill levels.

In computer C (Fig. 2), the address mothership 52
The central processing unit 50 has a data motherboard 54 and a random access memory 58, a read-only memory 56, a display device 62 via a display driver 60,
It is connected to the input/output section 63. The input/output section 63 includes an input/output control 64 connected to a timer 66, a beaver or other suitable alarm 67, and a keyboard matrix 68.

Timer 66 includes a free-running timer that functions as a computer real time clock for computer C. Central processing unit 50 accesses timer 66, which determines the date, hour, minute, and second of the current time to enable Computer 0 to obtain elapsed time.

Keyboard matrix 68 can be any of a number of commercially available computer data entry keyboards. Lead conductors 38 and 40 from the single-pole normally closed relay contacts 36 are connected to the keyboard matrix 68 across appropriate keys, such as bracket keys. Since the monopolar normally closed contact 36 is in its normally closed state when the ignition is off, the bracket key appears electrically depressed. Keyboard matrix 68 is used to enter new mileage intervals for various items stored in the monitor and to provide the monitor with date and time and mileage values for particular items.

Display device 62 indicates the current date and time to the vehicle operator or maintenance personnel when the vehicle is not running. When the vehicle's ignition switch 22 is closed, the display 62 indicates the number of miles remaining before applying the various recorded items. The display device 62 also transmits information to the central processing unit 50 obtained through the input/output control device 64 to the display driver 6.
Presented on the data bus 54 for 0, the display 62 can provide confirmation of the keyboard buttons pressed while entering new information.

Display device 62 is preferably a liquid crystal display to protect battery life and reduce system power requirements. The alarm 67 is accessible to the central processing unit 50 of the computer C via the input/output control device 64. In the preferred embodiment, alarm 67 is a beaver that provides an audible warning when an established interval for a maintenance item has elapsed.

Computer C operates on a series of control instructions stored in the form of a computer program, the steps of which are shown schematically in FIGS. 3A, 3B, 3C and 4. When the monitor is first energized, an initialization sequence 100 (Figure 3A) is executed to clear all data storage registers. 1st of sequence
The step is step 102, where an alarm flag is set to indicate that the alarm function is enabled. Next, step 104 prepares descriptions and initial values for various items used in connection with various maintenance items. The description is the name of the maintenance item to be monitored and is displayed in conjunction with the item's mileage value while the monitor is in operation to facilitate the owner's understanding of the displayed information. For example, maintenance items to be monitored in the preferred embodiment are oil changes, tire relocation, spark plug replacement, transmission fluid changes, belt changes, and brake servicing. Therefore, the maintenance interval values expressed in descriptive content and miles are 2000 for oil, 7000 for relocation, 1000 for spark plugs (2000), 20000 for transmission, 25000 for belt, and 35000 for brake. The second item is a speed factor called Speed with a value of 45.0 mph. This value is used along with elapsed time to determine the approximate number of miles traveled by the vehicle. After completing the initial configuration in step 104. , control is transferred to the main program sequence 110.

Main program sequence 110 is the main control loop of the program. Main program sequence 110
begins at step 112, where the current time is determined by reading timer 66. Step 114 follows,
The old time is made equal to the current time. This is done to avoid errors since there is a randomly generated initial old time. After step 114 is completed, step 11
6 determines the current time so that two times are available for calculation purposes.

Step 118 calculates the elapsed time by subtracting the old time from the new time. This value is then used in step 120 and multiplied by the speed factor to determine the approximate distance traveled during the elapsed interval. Although the estimated number of miles is inaccurate for a single interval, by choosing the speed factor appropriately this error is averaged out over a long period of time, and the overall number of miles traveled as indicated by this indirect method is Close enough to the actual number of miles traveled.

Next, step 121 sets a pointer to indicate the first of six maintenance items. Step 122 then subtracts the estimated distance from the remaining mileage value for the item indicated by the pointer. This reduces the mileage figure from either the initially preset value or the owner-entered value such that if that value reaches zero or becomes negative, maintenance work is attributed to that item. After an item's value has been updated, the item is displayed using the blue routine 200.
(FIG. 4) is displayed at step 124.

Once the display is complete, control returns to the decision stage, step 126. Step 126 determines whether a valid character was pressed on the keyboard. In the preferred embodiment, the valid characters at this stage are characters that are not relevant to control.

If no valid character has been pressed, control passes to step 127 where the pointer is incremented to indicate the next service item.

Following this, step 128 (Figure 3B) determines whether the last item has been completed. Only six maintenance items are displayed in this periodic format. The seventh item, which is the speed factor, is a constant and does not require any work, so it is not displayed at this point.

If step 128 determines that the last item is not updated and displayed, control passes to step 122;
The following items are processed: If the last item is displayed, control passes to step 130 where the current time is renamed as the old time and control passes to step 116 (FIG. 3A).
and starts a new calculation cycle. In the preferred embodiment, the average time for a computation cycle of six maintenance items is approximately 9 seconds, and each item takes approximately 1+ seconds to display.

If step 126 determines that a valid character has been pressed, control passes to step 132 (Figure 3B). Step 132 determines whether a number has been pressed. If no number keys are pressed, step 134 displays the date and time. In this way, the normal periodic display of items can be temporarily stopped and the monitor can be used as a clock. After displaying the date and time in step 134, control continues to step 136;
The date and time will be displayed again. Step 138
determines whether the pressed key was a parenthesis key connected to the single-pole normally closed contact 36, which is a relay contact. If so, control passes to step 136 where the date and time are redisplayed. A single-pole normally closed relay contact 36 is connected to the bracket key so that whenever the vehicle's ignition is turned off, the monitor module M remains in this loop and continuously displays the date and time. Is displayed.

If step 138 determines that the bracket key connected to the relay contact, unipolar normally closed contact 36, has not been pressed, control transfers to step 140. Step 140 sets the alarm plug to enable alarm and indication functions. This causes this portion of the program to be executed each time the vehicle is started, so that the alarm 67 is activated each time the vehicle is started.

It also sets an alarm plug if date display is required while the vehicle's ignition is on, allowing the owner to have an alarm function after starting the vehicle. After the alarm plugs out, control passes to step 112 and restarts the main program sequence 110.

If a character other than the parenthesis key connected to the single-pole normally closed contact 36, which is a relay contact, is pressed and the last item is not displayed, the remaining items are not updated. This creates a very small error in the amount of miles accumulated for these items.

However, this does not affect the accuracy of the overall monitor since each major loop routine typically runs for nine seconds, or the time the vehicle travels only part of a mile. Clock functions are typically not accessed frequently enough while the vehicle is running to affect long-term monitor accuracy.

If step 132 determines that a number key has been pressed, control transfers to step 142 (FIG. 3C), which determines whether the number is greater than seven. If so, return to control step 116. In this case, many items can be updated twice, but again one erroneous loop has no practical effect on the cumulative accuracy of the monitor.

If step 142 determines that the number is less than or equal to 7, control is transferred by step 144 to the display value subroutine 200 and the item corresponding to the pressed number is displayed.

This route is used to examine and optionally change specific maintenance items, eye remaining mileage numbers, or speed factor values.

After returning from display value subroutine 200, control continues to step 146 where a wait loop is initialized. Step 148 then determines whether a carriage return was entered on the keyboard. If not, control continues to step 150, where it is determined whether the wait loop is finished. If not, control continues to step 148 to form a loop. This loop allows the owner time to decide whether this is a suitable item to change, and thus indicates so by pressing the carriage return key. Once the wait loop is complete, control passes to step 116, which allows the program to continue if an erroneous item is selected.

If step 148 determines that a carriage return has been entered, step 152 enables new values for the selected service item to be entered from keyboard matrix 68 and displayed on display 62. After the new value is entered, control returns to step 116 of the main loop (third
Figure A〉.

In this way, the owner can change any value as desired and at any desired time. This allows a new interval to be reset after a service has been performed, allowing the owner to set the service interval to the number of miles desired by the individual rather than the number suggested by the manufacturer. This allows the vehicle operator or maintenance personnel to better match the maintenance interval to its preferred value and driving style and habits.

This adaptable feature also allows changes in mileage factors to better match an operator's driving routine. If the trip is generally a short trip in fairly heavy traffic, the speed factor should be low to accommodate the slow average speed and the maintenance interval should be short to accommodate the high stress on the vehicle components. Should.

Conversely, if the vehicle is used for long trips on generally open highways, a high speed factor and long mileage intervals may be used to reflect its high average speed and low vehicle stress. The monitor of the present invention can handle these individual variables very easily.

If a long high-speed trip is made in a vehicle with a monitor module M with a speed factor adjusted for a slow average speed, the actual mileage of the vehicle will be the approximate mileage determined by the monitor module M. This is an acceptable result. Maintenance intervals for high speed conditions are generally longer due to the lower stresses applied, so the apparent miscalculation may actually result in a better maintenance need than if the mileage estimate was actually accurate and the maintenance interval had not been changed. This is an approximate value. The same logic applies to high speed factor vehicles used for short trips. The number of miles determined by the monitor is greater than the actual number of miles, but more accurately reflects the stress level of the vehicle during the interval. These conditions assume that the speed factor is approximately accurate based on normal use of the vehicle. If different trips are made less regularly and more frequently, speed factors and service intervals must of course be changed to reflect changes in vehicle usage.

In a preferred embodiment, a parenthesis key connected to a single-pole normally closed contact 36 is detected as permanently electrically pressed so that the monitor module displays the date and time when the vehicle is off. It should be noted that these values can only be changed when the vehicle's ignition is on.

The display value subroutine 200 (FIG. 4) performs the tasks of displaying the value for a given item and sounding the appropriate alarm 67. The first step within the subroutine after entry is step 202, where the number of items is displayed over a period of time.

This is done to enable correlation between the numerical and descriptive representations of the items. After the item number is displayed, step 204 displays a description of the maintenance item and the remaining mileage number for that item. Next, step 206 determines whether the value is less than or equal to zero, indicating that the item should be serviced. If this is less than or equal to 0, control continues to step 208;
It is now determined whether the alarm flag is set. If set, step 210 activates the alarm for a period of time to alert the owner and clears the alarm flag. This clearing operation is performed because it is desirable for the alarm to be activated only after the vehicle is started or after a date and time request is made, rather than every time a particular item is displayed. After clearing the flag,
Control continues to step 212 and returns to the routine initialization sequence 100.

If the number of miles is zero or positive in step 206 or the alarm flag is cleared in step 208, control proceeds to step 212 and control returns to the calling routine.

The embodiments described above display each maintenance item during periodic display operations. If the number of maintenance items exceeds a large number, such as 6 or more, it is desirable not to display all the items.

This is due to the fact that the entire queue takes a considerable amount of time and requires the owner to wait for an extended period of time for the purpose of checking specific items of interest, especially items close to maintenance time. For this purpose. In another embodiment, only the three items closest to the item's service interval purpose are displayed. This makes it easier to monitor items close to maintenance.

Mileage values for all items are calculated first and the lowest three items are noted during update calculations. After the update is complete, three highlighted items will be displayed. After displaying the item, the computer then determines whether a valid key was pressed. A review of all items can be obtained by pressing a predetermined key on the keyboard 68 to cause the computer to run a different subroutine that displays all maintenance items.

As can be seen from the foregoing description, the monitor of the present invention is extremely easy to install and, moreover, is a highly flexible system that operates extremely well under normal conditions 73.

The foregoing disclosure and description of the present invention are exemplary and explanatory, and therefore, without departing from the technical idea of the present invention, details of the exemplary structure and theoretical flow, as well as its dimensions, shapes, etc. And various changes in materials can be made.

[Brief explanation of the drawing]

FIG. 1 is a schematic electrical circuit diagram showing the interface between a vehicle and the computer system of the present invention; FIG. 2 is a schematic diagram of the computer system of the present invention; FIGS. 3A, 3B and 3C are FIG. 4 is a flowchart illustrating the initialization and main program sequence of the present invention by way of a flowchart. FIG. [Explanation of symbols] C... Computer ■... Interface units 1 to M... Monitor module ■... Vehicle 50... Central processing unit 63... Input/output section 64... Input Output control device procedure amendment (flag) July 20, 1986

Claims (1)

[Scope of Claims] 1. A vehicle maintenance interval monitor comprising: a device for setting each of a plurality of maintenance intervals for a vehicle; a device for setting an estimated vehicle speed percentage value; and a vehicle operating time. a device that calculates the estimated distance traveled by multiplying the vehicle operating time by the estimated vehicle speed percentage value; a device that compares the estimated distance traveled with each maintenance interval; A vehicle maintenance interval monitor consisting of a device that indicates when one of the following has been exceeded. 2. A vehicle maintenance interval monitor according to claim 1, including a device for varying one of the maintenance intervals. 3. A vehicle maintenance interval monitor as claimed in claim 1 including a device for varying the estimated vehicle speed percentage value. 4. A vehicle maintenance interval monitor according to claim 3, including a device for varying one of the maintenance intervals. 5. The vehicle maintenance interval system according to claim 1, which includes a device for electrically connecting the monitor to the vehicle.
monitor. 6. Claim 5, wherein the electrically connecting device is connected to the vehicle's battery, ignition switch, and ground.
Vehicle maintenance interval monitor as described in section. 7. According to claim 1, wherein the vehicle operating time is determined in a plurality of intervals, the mileage is calculated for each time interval that becomes a distance interval, and the comparison is made on the accumulation of the distance intervals. Vehicle maintenance interval monitor listed. 8. A vehicle maintenance interval monitor according to claim 1, including a device for displaying each maintenance interval. 9. The vehicle maintenance interval monitor of claim 1 including a date and time display device. 10. The vehicle maintenance interval monitor of claim 9, wherein said display device includes a device that continuously displays the date and time when the vehicle ignition is turned off. 11. The vehicle maintenance interval monitor of claim 1 including a device for displaying vehicle percentage values. 12. The vehicle maintenance interval monitor of claim 1, wherein the indicating device includes an audible alarm. 13. The vehicle maintenance interval monitor of claim 1, wherein said indicating device includes a device for forming a video signal. 14. A method for monitoring vehicle maintenance intervals, the method comprising:
establishing a plurality of maintenance intervals; setting an approximate vehicle speed percentage value; determining vehicle operating time; computing an approximate mileage by multiplying the vehicle operating time by the estimated speed percentage value; A method for monitoring vehicle maintenance intervals comprising the steps of comparing the distance to each established maintenance interval and indicating when the calculated approximate mileage exceeds one of the established maintenance intervals. 15. A method for monitoring vehicle maintenance intervals as claimed in claim 14, comprising the step of changing one of the established maintenance intervals. 16. A method for monitoring vehicle maintenance intervals as claimed in claim 14, including the step of changing the estimated vehicle speed percentage value. 17. A method for monitoring vehicle maintenance intervals as claimed in claim 16, including the step of changing one of the established maintenance intervals. 18. The method of claim 14, wherein the steps of determining vehicle operating time and calculating and comparing estimated distances are performed continuously at the beginning of vehicle ignition.